The occurrence of mold formation in aluminum alloy die castings is the result of multiple factors working together. In terms of raw materials, the impurity content in the composition of aluminum alloy is crucial. If there are too many impurities such as iron and copper, micro cells will form on the surface of the die casting, accelerating electrochemical corrosion and leading to mold formation. In addition, insufficient degassing during alloy melting results in residual hydrogen and other gases forming pores inside the casting, providing entry channels for moisture and corrosive substances, promoting mold formation.

        The control of mold temperature, die-casting speed, and pressure in the die-casting process has a profound impact. Excessive or insufficient mold temperature can cause uneven solidification of aluminum alloy, resulting in structural defects and reduced corrosion resistance. If the die-casting speed is too fast, it is easy to draw in air and form pores; Insufficient pressure and insufficient density of castings increase the risk of mold formation. At the same time, improper use of release agents can also become a hidden danger. If the release agent contains corrosive components and remains on the surface of the die casting, it will react chemically with the aluminum alloy, leading to mold formation.

        During the subsequent processing, improper cleaning and protection are common causes of mold formation. Incomplete cleaning and residual impurities such as mold release agents and cutting fluids can corrode the die-casting parts. The passivation process is poor and cannot form a complete and dense passivation film, making it difficult to effectively isolate external corrosive substances. If the coating thickness is uneven and there are defects such as pinholes during painting, it cannot provide good protection for the die-casting parts, resulting in mold formation.

        The storage environment has a significant impact on the mold formation of aluminum alloy die-casting parts. In humid environments, moisture will adsorb onto the surface of die-casting parts, forming electrolyte solutions and causing electrochemical corrosion. If there are corrosive gases such as sulfides and chlorides in the environment, they will combine with water, accelerate the corrosion process, and lead to increased mold growth. In addition, when stacking and storing die castings, the contact areas are more prone to mold formation due to poor air circulation and relatively high humidity.